This project is a continuation of efforts to purify specific cell wall antigens of S. mutans for testing as possible caries vaccines. Monoclonal antibody technology has been initiated because of the potential to produce relatively large quantities of a desired antigen, free of contaminants. Glycosyltransferase (GTF) was chosen as the test antigen because of its role in bacterial colonization, its availability in a partially purified form and the existence of an assay procedure for detecting antibody inhibition of GTF activity. Spleen cells from two mice immunized with GTF were fused with P3X63Ag8.653 plasmacytoma cells at a ratio of 10:1. Cells were seeded into five 96 well microliter plates. Wells containing antibody producing cells were assayed by ELISA. Cells from 20 wells with highest antibody level were cloned. Twelve positive clones were expanded and six that continued to produce antibody in culture have been injected into pristane primed mice for ascites production.